Fantastical 2 - Fantastical, the Mac calendar app you'll enjoy using. Quickly create new events with natural language input and more.
Google Calendar - Spend less time managing your day & more time enjoying it
BusyCal - powerful calendar app for macOS
CalenGoo - Features | 1.0.175 for Android™
CalendarZ - CalendarZ is a simple yet high-level calendar application, introduced lots of advanced functions and features.
Superpowered - Power through the day without your calendar